Which device is designed to vary the amount of fuel delivered per revolution?

Which device is designed to vary the amount of fuel delivered per revolution?

• A. Variable displacement pump
• B. Fixed displacement pump
• C. Fuel injector
• D. Spark plug

Answer: (A)

The amount of fuel delivered per revolution is controlled by a variable displacement pump. This type of pump changes its displacement so that, with each turn, it pushes more fuel when the engine demands more and less when demand is lower. That adaptability keeps fuel pressure and delivery in line with load and speed. A fixed displacement pump always moves the same volume per revolution, so it can’t adjust to changing engine needs and would rely on other regulators to meter fuel. A fuel injector injects fuel into the cylinder under control signals, but it doesn’t vary the amount per revolution on its own. A spark plug is responsible for ignition, not fuel metering. Therefore, the device designed to vary the fuel delivered per revolution is the variable displacement pump.

The amount of fuel delivered per revolution is controlled by a variable displacement pump. This type of pump changes its displacement so that, with each turn, it pushes more fuel when the engine demands more and less when demand is lower. That adaptability keeps fuel pressure and delivery in line with load and speed. A fixed displacement pump always moves the same volume per revolution, so it can’t adjust to changing engine needs and would rely on other regulators to meter fuel. A fuel injector injects fuel into the cylinder under control signals, but it doesn’t vary the amount per revolution on its own. A spark plug is responsible for ignition, not fuel metering. Therefore, the device designed to vary the fuel delivered per revolution is the variable displacement pump.